Ethylene-vinyl aromatic telomer waxes and processes of preparing them

ABSTRACT

NOVEL WAX COMPOSITIONS CONTAINING ALKYL CYCLOALKYL STRUCTURES IN ADDITION TO ALKYL AROMATIC TELOMER STRUCTURES AND ALSO INCLUDING COPOLYMER TELOMER STRUCTURES. THESE WAX COMPOSITIONS HAVE A MOLECULAR WEIGHT RANGING FROM 500 TO 5000.

United States Patent US. Cl. 260-882 C 9 Claims ABSTRACT OF THEDISCLOSURE Novel wax compositions containing alkyl cycloalkyl structuresin addition to alkyl aromatic telomer structures and also includingcopolymer telomer structures. These wax compositions have a molecularweight ranging from 500 to 5000.

This application is a continuation-in-part of US. Ser. No. 85,781 filedOct. 30, 1970 entitled Synthetic Wax Process in the name of Arthur W.Langer, Jr.

This invention relates to a synthetic wax process. In one aspect, thisinvention relates to reacting ethylene in the presence of a chelatedlithium (LiR) catalyst with an aromatic or hydrocarbyl substitutedaromatic compound in the presence of an inert saturated hydrocarbonsolvent. In another aspect, this invention relates to a process in whichthe reaction conditions are selected to optimize activity of thecatalyst as well as its selectivity towards the production of a waxhaving a molecular weight ranging between 500 and 5000. In yet anotheraspect, this invention relates to novel Wax compositions containingethylene telomers which have both nahthenic and aromatic end groups.

In an earlier patent application, which has issued as Pat. No.3,458,586, a process is described therein for making synthetic waxes atlow rates or selectivities. In this process, alkyl aromatic compoundsare prepared by reacting an aromatic compound with ethylene attemperatures of 40 to 180 C. and pressures of at least 400 p.s.i.g. inthe presence of a catalyst system which is a combination of anonaromatic ditertiary amine with a lithium hydrocarbon. Each moleculeof the wax contains an aromatic end group as a result of an anionicchange transfer with the aromatic solvent.

In addition, Eberhardt and Davis have disclosed in Journal of PolymerScience 3, 3473 (1965) that by employing the same catalyst system in thepresence of a paratfinic solvent they were able to obtain olefins as thefinal product.

Pat. No. 3,290,277, issued to William S. Anderson and Stephen H. Levin,assigned to Shell Oil Company, teaches the preparation of new and novelamine-containing copolymers of alkyl styrene and ethylene wherein themonomers are copolymerized in the presence of an organolithium catalystand a nonchelating tertiary amine which functions not only as a solventand a cocatalyst, but also as a reactant.

A second Shell patent, U.S. 3,290,414, issued to William S. Anderson,relates to new and novel block copolymers of alpha alkyl styrene andethylene which are prepared by copolymerizing an alpha C -C alkylstyrene and ethylene in the presence of an oxygen or sulfur containingsolvent 3,790,541 Patented Feb. 5, 1974 and an organolithium catalyst ata temperature ranging from C. to 0 C.

The subject invention distinguishes from all of this prior art in thatit has now been discovered that novey synthetic waxes can be prepared inhigh selectivity by using critical reaction conditions which yield thedesired molecular weight waxes at high catalyst efficiencies. Thecatalyst system is similar to that disclosed in Pat. No. 3,458,586;however, the reaction with the aromatic compound is carried out in thepresence of a saturated hydrocarbon solvent.

One object of the subject invention is to provide a process forproducing synthetic waxes which permits a high yield of the desiredmolecular weight wax at high catalyst efiiciencies.

It is another object of the present invention to provide a process formanufacturing high melting synthetic waxes having number averagemolecular weights (fin) ranging from 500 to 5000 which containsubstantial amounts of alkyl cycloalkanes in addition to alkyl aromatictelomers and lesser amounts of aralkylcycloalkanes and normal paraflins.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description.

Briefly, this invention relates to reacting ethylene with a solventmixture consisting of either an aromatic compound or a hydrocarbylsubstituted aromatic compound, said compound containing up to about 30carbon atoms and having either aromatic or benzylic hydrogen sitesfalling Within a pKa range between about 32 and 38, and an inerthydrocarbon compound in the presence of a catalyst system comprising anorganometal compound such as butyllithium and a bifunctional Lewis base.The percent of aromatic compound in the mixture ranges from as low as 1%to 50% by volume. As the aromatic proportion is increased, productmolecular weight decreases and the wax contains a higher proportion ofalkyl aromatic molecules. Conversely, as the aromatic proportion isdecreased, Wax molecular weight increases and the Wax contains a higherproportion of alkyl cycloalkane structures.

The proportion of aromatic compound and the type of aromatic compoundmay be varied to control the wax molecular weight and properties. Theamount of aromatic compound determines the reaction temperature at whichcatalyst activity is sufficient to be commercially attractive to obtainproducts in the proper molecular weight range. The alkyl naphthenecontent of the wax is increased by decreasing the present aromaticcompound in the feed to range from 1 to 3 However, because the catalystactivity drops rapidly with decreasing aromatic concentration, it ispreferred to operate with at least 3% aromatic in the solvent mixture.Likewise, the naphthene content is decreased by increasing the percentaromatic from 20 to 50% or higher. However, product molecular weightdrops rapidly with increasing aromatic concentration and one losesselectivity to wax, so it is preferred to use less than 30% aromatic. Ofcourse, molecular weight could be increased by decreasing reactiontemperature but this is unattractive because of loss of activity.Therefore, the preferred aromatic concentrations are in the range of 3to 30 volume percent in a saturated hydrocarbon solvent.

The aromatic and hydrocarbyl substituted aromatic compounds which can beused contain up to about 30 carbon atoms and have either aromatic orbenzylic hydrogens falling within the range of pKa between about 32 and38 (i.e., i1 pKa units) based on the MSAD scale (D. J. Cram,Fundamentals of Carbanion Chemistry, Academic Press, New York, 1965, p.19). Suitable examples include benzene, toluene, xylene, mesitylenc,higher methylated benzenes, such as hexamethylbenzene or durene,ethyl'benzene, propylbenzene, higher alkylbenzenes, such aspentadecylbenzene, di-sec-dodecylbenzene or 1,2,4-triisopropylbenzene,cumene, t-butylbenzene, t-butyltoluene, 1,4-diisoamylbenzene, diphenyl,4,4'-dimethyldiphenyl, diphenylmcthane, 1,2 -diphenylethane,tetrahydronaphthalene, methyl and polymethyl naphthalenes, and mixturesthereof, including aromatic concentrates and solutions containingaromatics from refining processes such as aromatization. The termhydrocarbyl is to be limited in the subject invention to include onlyaryl, cycloalkyl and alkyl. In addition, aromatic heterocycliccompounds, such as methylpyridine, S-methylquinoline,methyldibenzothiophenes, etc. are also useful in this process. Ingeneral, increasing the number of methyl groups on the aromatic leads tomore facile chain transfer during telomerization and therefore yieldslower molecular weight wax. The most preferred aromatics for makingwaxes in the range 500-5000 M n are benzene, toluene, xylenes, and loweralkylbenzenes, and mixtures thereof.

The other constituent of the mixture is the inert hydrocarbon which canbe any paratfin, isoparaffin, cycloparaffin, or mixtures thereof. Thenumber of carbons is not critical but will usually be between 3 and 30.Preferably, the boiling point of the hydrocarbon is selected tofacilitate separation fro-m the products on recycle. Suitable examplesinclude butane, hexane, heptane, octanes, cyclohexane, methylcyclohexane, methyl cyclopentane, ethyl cyclopentane, propylcyclopentane, 1,3-methylheptocosane, saturated naphtha fractions, whiteoils, etc.

In the preferred embodiment, ethylene alone is polymerized with theforegoing mixture in contact with an organometal-bifunctional Lewis basecatalyst system in accordance with the present process. However, it ispossible to form copolymer telomers in which the copolymer telomers aremade by copolymerization of ethylene and an alpha alkylstyrene in thepresence of the above-identified aromatic-hydrocarbon solvent. The alphaalkyl group may be a C -C alkyl group preferably a methyl group; i.e.,alpha-methylstyrene. The copolymer telomer may contain between about 1%and 50%, preferably about 2 to 20% by weight of the alpha-alkylstyreneto modify properties such as adhesion, elongation, flexibility,compatibility and formulation with other waxes and additives, etc. Thealpha-alkylstyrene is preferably incorporated into the copolymer inrandom fashion since this produces the maximum effect with minimumamount. Other styrene monomers also may be used, especiallyarylalkylstyrenes.

The novel copolymer telomer waxes possess unique structures which impartimproved properties compared to the telomer waxes. The terminal ringstructures in combination with the comonomer units in the polymer chaingive increased flexibility and toughness while maintaining the desirableproperties of the unmodified telomer Waxes, i.e., high melting and highcongealing points, high tensile strength and low viscosities. Thesewaxes possess superior properties when used alone or in blends informulations with other natural or synthetic waxes, polymers oradditives. The combination of properties is superior to those of thecommercial synthetics such as polyethylene wax, ethylene-alpha-olefincopolymer wax, Fischer-Tropsch wax and other ethylene-based copolymerwaxes.

" The comonomer is a vinyl aromatic which may contain saturatedhydrocarbyl substituents on the ring or on the carbon alpha to the ring.Suitable examples include styrene (vinyl benzene); ring-substitutestyrene, such as arylmethyl styrene, 3,4-dirnet ylstyrene, py Styrene,

dodecyl styrene, eicosylstyrene, p-phenylstyrene and cysuch asalpha-methylstyrene, alpha-butylstyrene, alphamethyl-p-methylstyrene,stilbene, 4,4'-dimethyl-stilbene and the like. The most preferredcomonomers include mand p-alkylstyrenes and alpha-alkylstyrenes,especially the methyl derivatives.

The catalyst system is an organolithium compound in combination with achelating tertiary diamine. It is evident, however, that the desiredaryllithium may be prepared simply by metalating the aromatic prior toits use. This is accomplished by mixing the alkyllithium and thechelating agent in the aromatic solvent for a few minutes up to an hourat ambient temperature according to the following schematic equation:

The group RLi can be employed in this equation, wherein R is amonovalent hydrocarbon radical of 1 to 20 carbon atoms, preferably about1 to 8 carbon atoms. Examples of suitable R groups include alkyl,cycloalkyl, aryl, aralkyl or allyl but it is preferred to use the arylgroup corresponding to the aromatic compound used as chain transferagent in the telomerization. Thus, phenyllithium is preferred withbenzene solvent, benzyllithium with toluene solvent, etc.

Specific examples of R groups for substitution in the above formulainclude methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl,n-amyl, isoamyl, n-hexyl, n-octyl, n-decyl, and the like; allyl,Z-butenyl, 2-methyl- Z-butenyl and the like; cyclopentylmethyl,cyclohexylethyl, cyclopentylethyl, methylcyclopentylethyl and the like;cyclopentyl, cyclohexyl, 2,2,l-bicycloheptyl, and the like;methylcyclopentyl, dimethylcyclopentyl, ethylcyclo pentyl,methylcyclohexyl, dimethylcyclohexyl, ethylcyclohexyl,isopropylcyclohexyl, cyclopentadieneyl and the like; phenyl, tolyl,xylyl, ethylphenyl, naphthyl, naphthylmethyl, methylnaphthyl,methylethylnaphthyl, cyclohexylphenyl, and the like.

Particularly preferred as the first component of the catalyst system aren-butyllithium, phenyllithium and benzyllithium.

The second component of the catalyst system comprises a bifunctionalLewis base which is one selected from the group consisting of sparteine,N,Ndi-(C C alkyl)-bispidins and di(tertiary)-amines having the followinggeneral formulas:

wherein R R R and R are the same or different alkyl radicals of 1 to 4carbon atoms inclusive, A is a nonreactive group an x is an integer of 0to 3 inclusive. For the purposes of this invention, A in the aboveformulas is selected from the group consisting of (1) cycloaliphaticradicals and their lower alkyl derivatives having ring structurescontaining 5 to 7 members, wherein said radicals are attached to thenitrogen atoms at adjacent positions on the rings; suitable examplesinclude N,N,N',N'-tetramethy1 1,2 cyclopentanediamine, N,N, N,Ntetramethyl 1,2 cyclohexanediamine; and (2) 1 to 4 methylenic radicalsinclusive, wherein each methylenic radical contains 0 to 2 monovalenthydrocarbon radicals of 1 to 4 carbon atoms; suitable examples include1,2-dipiperidyl ethane, N,N'-dimethyl-N,N'-diethyl-1, Z-ethanediamine,N,N,N',N'-tetramethyl-1,2-pentanediamine,N,N,N',Ntetramethyl-1,2-propane-diamine, N,N,N',N-tetramethyl-2,B-butanediamine, N,N,N',N-tetramethyl- 1,4-butane diamine.

Particularly valuable as the second component of the catalyst system isan organic diamine having the general formula:

wherein R R R and R are the same or different alkyl radicals of 1 to 3carbon atoms inclusive and n is an integer between 1 and 4 inclusive. Inthe most preferred structures, n=2 or 3. Suitable examples include:

N,N,N,N'-tetramethyl-methanediamine, N,N-dimethyl-N',N'-diethyll,Z-ethanediamine, N,N,N,N-tetramethyl-1,2-ethanediamine,N,N,N,N'-tetraethyl-1,2-ethanediamine,N,N,N',N'-tetraethyl-1,2-ethanediamine,N,N,N,N-tetramethyl-1,3-propanediamine,N,N,N',N-tetramethyl-1,2-propanediamine,N,N,N',N-tetramethyl-1,4-butanediamine,

and the like.

In preparing and using this catalyst, all steps in the process should becarried out in the absence of moisture and preferably also in theabsence of oxygen or other harmful impurities. This may be readily doneby blanketing the materials with an inert gas, such as dry nitrogen orargon. The raw materials, i.e. both the reactants and inert liquids, maybe preferably purified or otherwise treated to remove traces ofmositure, oxygen, carbon di- 30 oxide and other catalyst poisons. It isgenerally desirable that the monomer stream should contain less thanabout 200 p.p.m. and the inert liquid less than about 50 p.p.m. byweight of the aforementioned impurities.

In practicing one embodiment of this invention, it is generallydesirable to prepare the catalyst system by premixing the selectedorganometal (i.e. the first component) with. the selected bifunctionalLewis base. However, the components may also be mixed in the presence ofethylene. Although a catalyst system comprising one organometal and onebifunctional base is preferred, mixtures of organometals andbifunctional Lewis bases may also be employed.

The molar ratio of the bifunctional Lewis base to the organo metal isfrom 10:1 to 1:2, preferably between about 5:1 to 1:1:

Reaction temperature ranges from 40 to 150 C., preferably 80 to 120 C.At the lower temperatures, catalyst activity declines normally. Aboveabout 120 C., activity declines as the catalyst decomposition reactionbecomes more prevalent. The optimum temperature for maintaining topcatalyst efiiciency is a range between 80 and 120 C. The reaction is runin the liquid phase.

Although the concentrations of the catalyst components are not critical,sufiicient amounts of the aromatic plus the hydrocarbon solvent arepreferably employed such that the concentration of the catalyst isnormally of the range from 0.01 to 20 grams per liter, preferably 0.1 to10 grams per liter of solution. It has been found that the catalystefliciency in this process is optimized with low catalystconcentrations.

As a matter of convenience, the individual catalyst components may bediluted prior to mixing. Standardized solutions of each catalystcomponent may be employed wherein the concentration of each solution isin the range of 0.1 to 5 N, preferably 0.5 to 2 N.

Although the temperatures required for the catalyst preparation are notcritical it is desirable to prepare the catalyst at temperaures rangingfrom about --50 to 100 C., preferably at temperatures in the range of 0to 80 C. Since the catalyst components, after mixing, normally result ina liquid mixture, the catalyst can conveniently be prepared atatmospheric pressure. The catalyst components are preferably mixed andstored in the aromatic solvent to be used in the telomerization in orderto obtain the desired aryllithium compound.

Ethylene pressure may be between about 500 and 5000 psi. or higher, butis preferably between 800 and 2000 p.s.i. Activity and molecular weightincrease with increasing ethylene concentration (pressure), sodirectionally one favors higher pressures until the costs associatedwith the high pressure equipment become excessive.

Reaction times range from about one half hour to 7 hours or more. Thechoice is made to achieve the desired production rate and catalystefliciency. The preferred times are 1 to 5 hours. The process may becarried out in either batch or continuous operation using stirred tanks,tubular reactors or other conventional equipment. In stirred tank units,cooling may be done by conventional cooling coils, by pump-around heatexchangers or by autorefrigeration using refluxing ethylene. In batchoperation, increased catalyst efliciency is obtained by adding all of itinitially.

The wax may be recovered by any conventional procedure such as flashinglight ends, precipitation, crystallization, extraction, etc. Thepreferred finishing process is described in the copending patentapplication filed on Oct. 30, 1970 hearing Ser. No. 85,606, whichincludes recycle of solvents, light ends and excess chelating agent.

The product from this process has a novel and most unexpectedcomposition. The waxes as well as the low molecular weight products madeunder the conventional telomerization conditions as described in US.Pat. 3,458,586 were entirely linear alkylbenzenes when benzene was usedas the reaction solvent. In this process, a large amount of naphthenicproduct is obtained in addition to some of the expected alkylbenzeneproduct.

Based on analysis of low molecular weight products, the alkyl naphthenesare predominantly alkyl cyclopentanes. However, it was not possible toidentify the ring-size in the higher molecular weight products socyclohexanes and higher ring structures, e.g. cycloheptane orcyclooctane, cannot be excluded.

The compositions are ethylene telomers containing predominantly bothnaphthenic and aromatic end groups. Their molecular weight ranges from500 to 5000.

The structure was shown to be naphthenic by intensive analytical studiesinvolving IR, NMR and GC/MS. An olefin structure, which also has C Hformula, was eliminated as a possibility for all products above C Thepro portion of naphthenic product varies inversely with the aromaticconcentration in the solvent mixture and may range from about 20 to molepercent or more. Since many natural waxes contain naphthene ringstructures, the products of this invention may be considered to berelated to natural waxes; however, they are of much higher purity,higher melting, harder, etc., than the natural waxes by virtue of thelinearity of the polyethylene chains attached to the ring structures(both naphthenic and aromatic).

The waxes are of very high quality as measured by color, softeningpoint, melting point, molecular Weight, molecular weight distribution,hardness, gloss, congealing temperature, etc. They are useful asadditives for a wide variety of polymers and wax formulations to impartvarious desirable properties to the mixtures.

In another embodiment of this invention, olefins or diolefins may beused in place of aromatic compounds as chain transfer agents undersimilar conditions. The waxes obtained in this case are mixtures ofethylene telomers containing both olefinic and naphthenic end groups.The use of olefins in place of aromatics also leads to high activitiesand wax selcctivities when utilized in similar concentrations and undersimilar conditions. The olefins preferably contain between about 4 and30 carbons. Suitable olefins include alpha olefins such as butene-l,pentene- .1, hexene-l, dodecene-l, eicosene-l, and the like, internalolefins such as butene-2, octene-3, decene-4 or mixtures of double bondisomers including mixtures obtained from isomerization of alpha olefins,and branched or cyclic olefins, such as isobutylene, 2,3dimethylbutene-l, 2,3-dimethyl-butene-Z, Z-ethylhexene-l,2-dodecylhexadecene-1 cyclohexene, cyclooctene, etc. Suitable diolefinsinclude isoprene, 2,3-dimethylbutadiene, piperylene, 2,4-hexadiene, etc.

The following examples are given below to illustrate the preparation ofthe types of products described hereinabove.

EXAMPLE 1 A 0.5 M solution of Li-2TMED in benzene was prepared by aginga 0.5 M BuLi-ZTMED solution for 4 days at 25 C. A solution of 3 mmolesLi-2TMED in 25 ml. benzene was pressured into the reactor with ethylene.The reactor contained 475 ml. n-heptane at 95 C. and 800 p.s.i.g.ethylene pressure. Reaction conditions of 100 C. and 1000 p.s.i.g. werereached within a few minutes and maintained for 5 hours The totalreactor solution was flashed into 1 liter H in a 1. flask and gaseousproducts were vented. The slurry was distilled through a 7 in. Vigreauxcolumn until 500 ml. H O was taken overhead in addition to the volatilehydrocarbon solvents and light ends. The wax slurry was dispersed in aWaring Blender, filtered from the water solution of catalyst residues,rinsed with water and vacuum dried at 8085 C. The yield of wax was 117g.; fin (Number average molecular wt.)=1509; Fisher-Johns softeningpoint=2l7 F.; Plateau melting point =240.5 F.

EXAMPLE 2 The procedure of Example 1 was followed except that 75 ml.benzene and 425 ml. n-heptane vol. percent benzene) were used instead of5% benzene. Wax yield =189 g.; softening point=183 F.; melting point==236 F.

EXAMPLE 3 The procedure of Example 1 was followed except that 55 ml.benzene and 450 ml. n-heptane (10.9 vol. percent benzene) were usedinstead of 5% benzene. Wax yield -=211 g.

EXAMPLE 4 TABLE I Benzene, vol. percent in n-heptane 5 10. 9 15 ax Mn 1,509 1,357 1,249 Alkylbenzenes, mole percent 1 40 66 Alkylnaphthenes,mole percent 60 43 -34 1 Includes aralkylcycloalkanes. 1 Includesn-parafi'ins.

The mechanism for formation of alkylnaphthenes may involve formation oftransient TMED- LiH or it may require participation of ethylene toproduce TMED-LiC H directly.

EXAMPLE 5 The procedure of Example 1 was followed except that severaldifierent aromatics were used, the catalysts were prepared by mixingBuLi+TMED in the aromatic for 15-35 min. to obtain the ArLi-TMED, andthe products were isolated by precipitation with 1 liter isopropylalcohol, filtration, recrystallization from 5 volumes alcohol,filtration and vacuum drying at 70 C.

The results summarized in Table II show that a variety of aromaticcompounds may be used in this process. In general, increasing the numberof methyl groups on the aromatic results in more rapid chain transferand yields lower molecular weight total products. Secondary and tertiarybenzylic hydrogens are succeedingly less reactive and reactivity of thearomatic hydrogens becomes competitive.

TABLE II TMED/qBLi, mmolcs 6/6 6/6 6/6 12/6 Aromatic Benzene TolueneXylene Tetralin Vol percent in n-heptane.. 2/0 20 5 10 Temp., C 100 100100 Time, hrs 5 5 5 5 Wax:

Yield, g. a 127 104 198 Selectivity, percent b 90 82 92 92 Mn 1, 247 1,018 1, 490 1, 799

A Product Csu-4o. b Excludes volatiles lost during drying light ends.

EXAMPLE 6 The procedure of Example 5 was followed except thattemperature was varied while holding the percent xylene constant.

TABLE III (6 moles Li-TMED; 5 vol. spircegit xylene in 11-0 1,000p.s.i.g.;

Temp., 0 90 100 Wax:

Yield, g 69 104 47 Selectivity, percent... 93 92 76 The results showthat activity is optimum at about 100 C. The decrease in activity above100 C. is due to catalyst decomposition, Whereas the decrease below 100C. is the normal temperature elfect on reaction rate. Wax molecularweight decreases rapidly with increasing temperature. Therefore,temperature is an effective variable for controlling molecular weight,in addition to the aromatic concentration (Table 1).

EXAMPLE 7 The procedure of Example 6 was followed except that bothtemperature and benzene concentration were varied.

erization temperature has a greater elfect than a fourfold change inbenzene concentration on the wax molecular weight. The increased benzeneconcentration should have decreased molecular weight but the opposingeffect of decreased temperature prevailed. Also, as shown previously inExample 6, the maximum wax yield was obtained at 100 C.

EXAMPLE 8 The procedure of Example 3 was followed except that ethylenepressure was varied while holding other variables constant.

TABLE V (3 moles Ll-2TMED; 10.9% CiHs in n-O' 100 0.; 5 hrs.)

C2H4, p.s.i.g 850 950 1, 050 Wax:

Sott. p F 163 192 208 Melnng point, F 237 238 239 The wax yieldincreased almost linearly with increasing ethylene pressure, showingthat higher activities and higher catalyst efficiencies may be obtainedby further increases in pressure. However, these are compensated byhigher costs for pressure equipment which allows one to calculate theeconomic optimum. There should be a small increase in molecular weightwith increasing pressure, but small variations in the amount of lightends present were more important.

EXAMPLE 9 The procedure of Example 3 was followed except that the ratioof TMED/Li was varied.

TABLE VI (10.510.9% CeHs in Il-C7; 100 0.; 1,000 p.s.i.g.; 5 hrs.)

"I;,MED/L1 mole ratio 3/3 6/3 9/3 Yield, g 60 195 219 Mn 1, 413 1, 3551, 308

EXAMPLE 10 The procedure of Example 3 was followed except that thecatalyst was 2 mmoles Li-3TMED and it was added in increments during thereaction rather than all initially. At the start, 1 mmole Li-3TMED in 43ml. benzene was added to the reactor containing 450 ml. n-heptane and800 p.s.i.g. ethylene at 96.5 C. Pressure and temperature wereimmediately raised to 100 C. and 1000 p.s.i.g and maintained for 5 hoursAfter each hour for 3 hours, an additional 0.33 mmole Li-3TMED in 6 m1.benzene was pressured into the reactor. The reaction mixture wasrecovered as in Example 1 after a total of 5 hours reaction time basedon the first charge of catalyst. In another experiment, 3 mmoles ofLi-2TMED catalyst was added in increments during the reaction. Theseresults are compared in the table below with experiments in which thetotal catalyst was charged initially as in Example 3.

TABLE VII Li/TMED, mmoles... 3/6 2/6 3/6 2/6 Catalyst addition.Incremental Initial charge Total Total 1/6 1/6 Number of additions- 3 3Amount per addition... 1/6 1/6 Wax yield, g 209 137 271 248 Mn 1, 309 1,336 1; 424 1, 393

1 Regular.

A run was made in a continuous polymerization unit having 540 ml. liquidvolume. The catalyst preparation, polymerization conditions and productrecovery were carried out according to the procedure of Example 3. Asolution of 3.93 mmolar Li-3TMED in 10.9% benzone-89.1% n-heptane waspumped continuously into a stirred reactor maintained at 100 C. and 1000p.s.i.g. ethylene pressure. The liquid phase reactor product was removedsemi-continuously to maintain the liquid volume in the reactor at 540ml. At a residence time of 2.61 hours, the wax concentration in thereactor product was 28 Wt. percent based on benzene plus heptane, andthe wax production rate was 1080 g./hr./g. BuLi. The wax Mn: 1358.

In other continuous runs, the variables studied in cluded TMED/Li moleratio (24), catalyst concentration (3.93-7.'87 mmoles qsLi/liter) andresidence time (1.5-4 hrs.). Wax concentratons ranging from 24- 44 wt.percent were obtained at the various production rates.

EXAMPLE 12 A copolymer telomer was prepared by telomerizing ethylene inthe presence of 23.5 g. alpha-methylstyrene (freshly distilled fromcalcium hydride). The alphamethylstyrene and 450 ml. n-heptane werecharged to the autoclave, the solution was heated to C. while C Hpressure was raised to 800 p.s.i.g., then a solution of 3 mmolesLi-2TMEDA in 55 ml. benzene was added and the system was brought rapidlyto C. and 1000 p.s.i.g. After one hour, an additional 3 mmoles Li-2TMEDAin 6 ml. benzene was added and the reaction was continued an additional2 hours at 100 C. and 1000 p.s.i.g. The product was isolated as inExample 1, yielding 138.3 g. wax, Mn=1414. The wax had no Plateaumelting point, indicating that it was amorphous and therefore randomcopolymer telomer. NMR analysis showed the presence of 2.20 aromaticrings per molecule, including the phenyl end-groups from the benzenesolvent.

EXAMPLE 13 The procedure of Example 12 was followed except that only 6.0g. alpha-methylstyrene was charged. The yield of wax--2l8.8 g.;fin=1285; Plateau M.P.=234.5 F.

EXAMPLE 14 The procedure of Example 12 was followed except that 32.05 g.t-butylstyrene (freshly distilled from calcium hydried) was used. Thewax yield was 289.9 g.; Mn=1461; Plateau M.P.=238 F. The melt was cloudyat 250 F. indicating some incompatibility due to block structure or thepresence of some homopolymer.

EXAMPLE 15 The procedure of Example 12 was followed except that 20.8 g.freshly distilled styrene was used and no additional catalyst was addedafter the initial charge of 3 mmoles Li-2T-MEDA. Wax yield=173.7 g.;Mn=1426; Plateau M.P.'=237.5 F. The melt was cloudy as in Example 14.

EXAMPLE 16 A copolymer telomer was prepared by feeding 5 0 ml. of aheptane solution containing 10 g. alpha-methylstyrene to the reactorduring 4.5 hrs. at 100 C. and 1000 p.s.i.g. C H pressure. At the start,the reactor contained 450 ml. n-heptane and 41 ml. benzene plus 1 mmoleLi- 3TMEDA After hours 1, 2, 3 and 4, an additional 0.5 mmole Li- 3TMEDAin 5 ml. benzene was added. After 5 hours reaction time, the product waspressured from the reactor and recovered as in Example 1. Yield: 117.7g.; Mn: 1260; Plateau M.P.=224 F.; Brookfield viscosity =53.7 cps. at275 F. and 41.0 cps. at 300 P. NMR analysis showed 0.79 aromatic ringsper molecule includ ing the terminal phenyl groups from chain transferto benzene solvent. Homotelomer contains only about 0.5

1 1 aromatic right per molecule under these conditions. Therefore, thecopolymer telomer contains about one alphamethylstyrene for every 3-4telomer molecules.

EXAMPLE 17 The procedure of Example 12 was followed except that g.arylmethylstyrene was used. Wax yield=277 g.', Mn=l455; Plateau M.P.=238P. NMR analysis found 0.99 aromatic rings per molecule.

EXAMPLE 19 The procedure of Example 16 was followed except that reactiontemperature was 110 C. and l mrnole Li-3TMEDA catalyst was added hours1, 2, 3 and 4, making the total catalyst charge=5Li-3TMEDA. Yield: 144.8g.; Mn=l016; Plateau M.P.=222 H; NMR ana1ysis=0-.79 aromatic rings/molecules.

EXAMPLE 20 The procedure of Example 12 is followed except'that 0.1 molestilbene is used. The copolymer telomer wax contains stilbeneincorporated in the chain.

EXAMPLE 21 on the carbon atoms on the ring or on the carbon atom alphato the ring containing from to 90 mol percent of naphthenic end groupswith the balance being predominantly aromatic end groups.

2. A wax according to claim 1 wherein the styrene derivative constituentis t-butylstyrene.

3. A wax according to claim 1 wherein the styrene derivative constituentis alpha-methylstyrene.

4. A wax according to claim 1 wherein the styrene derivative constituentis arylmethylstyrene.

5. A process for making synthetic waxes having a number averagemolecular weight ranging from 500 to 5000, said process comprising thestep of copolymerizing ethylene with either styrene or a substitutedderivative thereof wherein the substituents are saturated hydrocarbylgroups located either on the carbon atoms on the ring or on the carbonatom alpha to the ring in a solvent mixture containing from 3 to volumepercent aromatic or aromatic substituted with alkyl, cycloalkyl and arylin a saturated hydrocarbon solvent with a catalyst consistingessentially of RLi where R is a mouovalent hydrocarbon radicalcontaining from 1 to 20 carbon atoms and a bifunc tional Lewis 'basewhich is one selected from the group consisting of sparteine; N,N'-di(C-C alkyl) -bispidins and di- (tertiary) amines characterized by theformulae:

R{\ /Ra /CE2 /CH2 /NAN (0g2). N-AN\ BCHQ), R2 R4 CH2 CH3 wherein R R isthe same or different and is a C to C saturated alkyl radical, x is aninteger of 0 to 3 inclusive, and A is selected from the group consistingof:

These waxes have been found to be very useful as in- (a) cycloaliphaticradicals and their lower alkyl desulating materials in the manufactureof electric power rivatives having ring structures containing 5 to 7cables to improve the breakdown voltage thereof. These members, whereinsaid radicals are attached to the advantages are achieved by the factthat this wax is a solid nitrogen atoms at adjacent positions on therings; at room temperature and possesses a melting point near (b) 1 to 4methylenic radicals inclusive, wherein each or above 200 F. However, inspite of its high melting 40 radical contains 0 to 2 monovalenthydrocarbon radipoint, this wax can act as a diluent in place ofextruder cals of 1 to 4 carbon atoms under reaction conditions oil whileimparting at the same time, a better dielectric sufiicient to maintainthe ethylene in the liquid phase. strength to the finished cable withoutadversely affecting 6. A process as defined in claim 5 wherein thearomatic other physical properties. These advantages are demonandaromatic compounds substituted with alkyl, cyclostrated in the followingtable. alkyl and aryl are each selected from the group consisting TABLEVIII Composition in pphn:

Polyethy 100 100 70 30 30 Ethylene/propylene copolymer containing 43% byweight ethylene having a molecular weight; in the range oi170,000 to m30 30 70 70 100 100 Alkylbenzene wax..- 10 10 10 1O 20 Polymerizedtrimethyldihydroquinoline 0.5 0.5 1.0 1.0 1.0 1.0 1.0 1.0 1.0 Treatedcalcined clay 110 110 110 110 Trialkylcyanurate 0.75 0.75 0.75 0.75 1 11 1 1 Dicnmylpernxida 2.7 2.7 2.7 2.7 2.7 2.7 2.7 2.7 2.7 Physicalproperties:

Shore A hardness 96 97 88 92 S4 88 66 73 74 100% modulus 400 460 450Percent elongation 10 280 260 320 Tensile strength 1,050 1,050 950Average thick, mils 38 36 34 Dielectric strength, kv./mil 1.38 1. 621.73

1 According to ASTM D149-64, using a rate of0 of 500 v./sec. and Ielectrodes. All samples were prepared in the same manner in a BauburyBlender and cured. for 20 min. at 32 The dielectric strength resultindicates a definite advantage for these samples containing thealkylbenzene wax, i.e., samples 2, 4, 6, 8 and 9.

The advantage derived from the use of alkylbenzene wax is furtherenhanced by the fact that this wax is a solid at room temperature and amelting point near or above 200 F.

What is claimed is:

1. A synthetic wax having a number average molecular weight ranging from500 to 5000, said wax being characterized in that it comprises acopolymer of ethylene and styrene or substituted derivatives thereofwherein the substituents are saturated hydrocarbyl groups located either3 14 methyl styrene and the Lewis base is N,N,N',N'-tetra- 3,290,27712/1966 Anderson et a1. 260--88.2 C methyl 1,2-ethane diamine. 3,338,8778/1967 Anderson 260-882 C References Cited JOSEPH L. SCHOFER, PrimaryExaminer UNITED STATES PATENTS 5 E. 1. SMITH, Assistant Examiner3,652,696 3/ 1972 Honeycutt 260-949 R 3,450,795 6/1969 Langer 260-94.9 RCL 3,639,380 2/1972 Screttas 26094.9 R 26()33.6 PQ, 85.3 R, 94.9 R, 668B, 897 A 3,115,468 12/1963 Emrick 260-949 R UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION P atent No. 3,790,541 Dated bruaryfi, 1974Arthur W. Langer, Jr.

Inventor(s) It is certifiegi that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Colunm 12, line 64, PKA" should read 1 at-,-';

Signed and 'ealed this 26th day November 1974.

(SEAL' Attest: McoY M. GIBSON'JR. CQMARSHALL DANN Attesting OfficerCommissioner of Patents I FORM PO-IOSO (10-69) UscMM Dc 376 p59 h 9 nos.eovnimsu'r rnnmue ornc: nu 0-3Gi-33l,

PatentNo. 4 Dated February 4 lnventofls) Arthur W. Langer, Jr.

It is certified that error appears in the above-identified patent andthat said Letters Patentare hereby corrected as shown below:

line 36, "nahthenic" should read naphthenic Column 1,

Column 2, line 4, "novey" should read novel Column 4, line 56, "an"before "x" should read and Column 9, line 55, 1 /6" (both) should read1/2 Signed and sealedCthis 17th day of September 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN Attesting Officer Commissioner ofPatents nosg) us'coMM-Dc 8O376-P59 .5. GOVERNMENT PRINTING OFFICE: IBB0-356-334,

